style changes in server sorting option descriptions

config/conf.pl

@@ -342,8 +342,6 @@ $provider_uri = ''                      if ( !$provider_uri );
 $provider_name = ''                     if ( !$provider_name );
 $edit_identity = 'true'                 if ( !$edit_identity );
 $edit_name = 'true'                     if ( !$edit_name );
-$disable_thread_sort = 'false'         if ( !$disable_thread_sort );
-$disable_server_sort = 'false'         if ( !$disable_server_sort );
 $no_list_for_subscribe = 'false'        if ( !$no_list_for_subscribe );
 $allow_charset_search = 'true'          if ( !$allow_charset_search );
 $allow_advanced_search = 0              if ( !$allow_advanced_search) ;
@@ -410,6 +408,9 @@ $use_imap_tls = 0                      if ( $use_imap_tls eq 'false');
 $use_imap_tls = 1                      if ( $use_imap_tls eq 'true');
 $use_smtp_tls = 0                      if ( $use_smtp_tls eq 'false');
 $use_smtp_tls = 1                      if ( $use_smtp_tls eq 'true');
+# sorting options changed names and reversed values in 1.5.1
+$disable_thread_sort = 'false'         if ( !$disable_thread_sort );
+$disable_server_sort = 'false'         if ( !$disable_server_sort );
 
 if ( $ARGV[0] eq '--install-plugin' ) {
     print "Activating plugin " . $ARGV[1] . "\n";
@@ -2278,17 +2279,19 @@ sub command311b {
 }
 
 sub command312 {
-    print "This option makes it possible to disable the use of thread sorting if your server\n";
-    print "supports thread sort. Your IMAP server must support the THREAD command for this\n";
-    print "to have any effect.\n";
+    print "This option allows to disable server side thread sorting if your server \n";
+    print "declares THREAD support, but you don't want to provide threading options \n";
+    print "to end users or THREAD extension is broken or extension does not work with \n";
+    print "options used by SquirrelMail. Option is not used, if THREAD extension is \n";
+    print "not declared in IMAP CAPABILITY.\n";
     print "\n";
 
-    if ( lc($allow_thread_sort) eq 'true' ) {
+    if ( lc($disable_thread_sort) eq 'true' ) {
         $default_value = "y";
     } else {
         $default_value = "n";
     }
-    print "Disallow server side thread sorting? (y/n) [$WHT$default_value$NRM]: $WHT";
+    print "Disable server side thread sorting? (y/n) [$WHT$default_value$NRM]: $WHT";
     $disable_thread_sort = <STDIN>;
     if ( ( $disable_thread_sort =~ /^y\n/i ) || ( ( $disable_thread_sort =~ /^\n/ ) && ( $default_value eq "y" ) ) ) {
         $disable_thread_sort = 'true';
@@ -2299,9 +2302,13 @@ sub command312 {
 }
 
 sub command313 {
-    print "This option makes it possible to disable server-side sorting if your server\n";
-    print "supports server side sorting. Your IMAP server must support the SORT  command\n";
-    print "for this to have any effect\n";
+    print "This option allows to disable server side sorting if your server declares \n";
+    print "SORT support, but SORT extension is broken or does not work with options \n";
+    print "used by SquirrelMail. Option is not used, if SORT extension is not declared \n";
+    print "in IMAP CAPABILITY.\n";
+    print "\n";
+    print "It is strongly recommended to keep server side sorting enabled, if your ";
+    print "IMAP server supports it.";
     print "\n";
 
     if ( lc($disable_server_sort) eq 'true' ) {
@@ -2309,7 +2316,7 @@ sub command313 {
     } else {
         $default_value = "n";
     }
-    print "Disallow server-side sorting? (y/n) [$WHT$default_value$NRM]: $WHT";
+    print "Disable server-side sorting? (y/n) [$WHT$default_value$NRM]: $WHT";
     $disable_server_sort = <STDIN>;
     if ( ( $disable_server_sort =~ /^y\n/i ) || ( ( $disable_server_sort =~ /^\n/ ) && ( $default_value eq "y" ) ) ) {
         $disable_server_sort = 'true';